It is desirable to have threaded locking fasteners such as a nut and one or two lock washers retained in a preassembled condition to prevent the washers from being mounted in a reverse position when the nut is used as a fastener. The prior art discloses the use of a cylindrical pilot or sleeve carried on the nut. The washer is mounted on the sleeve. The lower end of the sleeve is flared outwardly to a diameter greater than the central hole in the washer to retain the washer on the nut.
Examples of such prior art may be found in U.S. Pat. Nos. 3,238,581 issued Mar. 8, 1966 to Frank L. Sawyer for xe2x80x9cToggle Latch Constructionxe2x80x9d, see FIG. 4; 3,680,619 issued Aug. 1, 1972 to Harold R. Sparks for xe2x80x9cLock Washerxe2x80x9d, see FIG. 8; 4,140,870 issued Feb. 20, 1979 to Jack C. Volkers et al. for xe2x80x9cCable Ground Systemxe2x80x9d, see FIG. 5; 4,362,449 issued Dec. 7, 1982 to Emil J. Hlinsky for xe2x80x9cFastener Assembliesxe2x80x9d, see FIG. 4; 5,190,423 issued Mar. 2, 1993 to Paul E. Ewing for xe2x80x9cLocking Fastenerxe2x80x9d, see FIG. 5; 5,203,656 issued Apr. 20, 1993 to Alistair N. McKinlay for xe2x80x9cSelf-Centering, Self-Tightening Fastenerxe2x80x9d, see FIG. 5; 5,314,279 issued May 24, 1994 to Paul E. Ewing for xe2x80x9cLocking Fastenerxe2x80x9d, see FIG. 5.
U.S. Pat. No. 2,679,850 issued Jun. 1, 1954 to O. J. Poupitch for xe2x80x9cCoupled Nut and Lock Washerxe2x80x9d shows a similar instruction but in which the lower end of the cylindrical pilot has an annular flange for retaining the washer.
The preferred embodiment of the invention comprises a wedge type locking nut and washer assembly comprising a nut and two washers connected together by a split ring retainer. The nut has a cylindrical pilot that extends along the turning axis of the nut beneath the camming face of the nut head. The length of the pilot is sufficient to mount a hex flanged nut and an inverted cup-type washer. The split ring retains the two washers on the pilot in a preassembled position with respect to the nut. For illustrative purposes, the hex flange nut has a cammed surface that faces and engages the cammed surface on the nut. The bottom surface of the hex flanged nut has an annular array of mini cams that is engageable with an annular array of similarly-shaped mini cams on the cup-shaped washer. The center portion of the cup-shaped washer has a concave configuration enclosing the retainer to permit the lower side of the cup-washer to engage the workpiece without interference with the pilot.
Still further objects and advantages of the invention will become readily apparent to those skilled in the art to which the invention pertains upon reference to the following detailed description.
The description refers to the accompanying drawings in which like reference characters refer to like parts throughout the several views, and in which:
FIG. 1 is a sectional view taken through a fastener assembly illustrating the invention. The fastener assembly is shown securing two workpieces together.
FIG. 2 is a view of a split ring used for holding the nut and washers together as a unit;
FIG. 3 is a view of a resilient ring that can be used as a substitute for the ring of FIG. 2;
FIG. 4 is a plan view of the preferred nut;
FIG. 5 is a side view of the preferred nut, showing the pilot;
FIG. 6 is a view of the nut as seen from the bottom of FIG. 5;
FIG. 7 is a plan view of the preferred hex flange washer;
FIG. 8 is a side view of the preferred hex flange washer;
FIG. 9 is a bottom view of the hex flange washer;
FIG. 10 is a side view of the cup washer; and
FIG. 11 is a top view of the cup washer showing the mini cams.